Dorsal Approach to the Scaphoid

Hand & WristIntermediateCore Procedure

Dorsal Approach to the Scaphoid

Comprehensive operative guide to the dorsal approach to the scaphoid for proximal-pole fixation and nonunion grafting - supine positioning, Lister's tubercle landmark, 3rd and 4th extensor compartment interval, preservation of the dorsal ridge blood supply, and antegrade headless compression screw placement for Orthopaedic exam

High-yield overview

Supine exposure of the proximal pole and waist β€” flex the wrist to deliver the proximal pole, place an antegrade central screw, and preserve the dorsal ridge vessels.

70 to 80%Scaphoid supplied by the dorsal ridge vessels
SupinePatient positioning
Lister's tubercleKey dorsal landmark
3rd / 4thExtensor compartment interval (EPL to EDC)
Critical Must-Knows
  • No true internervous plane. The working interval is inter-compartmental, between the 3rd extensor compartment (EPL) and the 4th (EDC and EIP); every dorsal extensor tendon is supplied by the posterior interosseous nerve.
  • Preserve the dorsal ridge vessels. The dorsal carpal branch of the radial artery enters along the dorsal ridge and supplies 70 to 80 percent of the scaphoid, including the entire proximal pole.
  • Wrist flexion over a bolster is the key exposure manoeuvre: it rotates the scaphoid and delivers the proximal pole dorsally into the wound.
  • The dorsal sensory branch of the radial nerve is the most important superficial structure at risk; its branches lie immediately deep to the skin.
  • The dorsal route is preferred for proximal pole fractures and nonunion grafting because it allows a true antegrade (proximal-to-distal) central screw and direct visualisation of the proximal pole.
  • Mobilise the EPL radially out of the 3rd compartment and repair the retinaculum at closure to prevent bowstringing and late EPL rupture.

When & Why

What it exposes. The dorsal approach gives direct visualisation of the proximal pole and the waist of the scaphoid β€” the segments most at risk of nonunion and avascular necrosis β€” and it is the only route from which a true antegrade (proximal-to-distal) headless compression screw can be placed centrally along the long axis of the bone. It also allows anatomic restoration of the articular surface and insertion of a bone graft into a dorsal trough when required. Why dorsal (and not volar). The dorsal approach is chosen whenever the target is the proximal pole or a nonunion: the entry point for an antegrade screw lies at the proximal pole, which is only safely accessible from the dorsal side. The volar (RussΓ©) approach, by contrast, is the workhorse for distal pole and most waist fractures, where a retrograde (distal-to-proximal) screw avoids violating the trapezium and protects the dorsal blood supply. Indications: - Displaced proximal pole scaphoid fractures requiring open reduction and internal fixation

  • Scaphoid nonunions, especially of the proximal pole and waist, requiring bone grafting
  • Nonunion with avascular necrosis (AVN) of the proximal fragment requiring vascularised bone grafting
  • Percutaneous antegrade (dorsal) screw fixation of minimally displaced proximal pole and waist fractures
  • Proximal pole fragment excision for small comminuted unfixable fragments
  • Scaphoid excision as part of salvage procedures (proximal row carpectomy, four-corner fusion) for SNAC or SLAC patterns Contraindications: - Distal pole or tubercle fractures β€” better accessed through the volar (RussΓ©) approach; a dorsal antegrade screw would risk penetrating the trapezium or leaving the distal fragment unsupported
  • Severe comminution of the dorsal ridge that would jeopardise the remaining blood supply if exposed
  • Active infection of the dorsal wrist skin or septic arthritis
  • Poor soft tissue envelope over the dorsum (relative β€” delay until recovered) Alternative approaches: - Volar (RussΓ©) approach β€” the workhorse for distal pole and most waist fractures; uses a retrograde (distal-to-proximal) screw
  • Lateral (radial) approach via the anatomical snuffbox β€” limited access to the waist and some percutaneous techniques; risks the radial artery and superficial radial nerve
  • Arthroscopically assisted percutaneous fixation β€” for minimally displaced fractures where reduction is confirmed arthroscopically
  • Combined dorsal and vascularised graft approaches (such as the 1,2 intercompartmental supraretinacular artery pedicled graft) β€” for recalcitrant nonunion with AVN
Approach variants
VariantWhat it isTypical use
Open dorsalLongitudinal capsulotomy between the 3rd and 4th extensor compartmentsDisplaced proximal pole ORIF, nonunion bone grafting
Percutaneous dorsalAntegrade guidewire placed through a flexed wrist without an open capsulotomyUndisplaced or minimally displaced proximal pole
Extended dorsalIncorporates the distal radius or carpusNonunion with AVN, vascularised bone grafting, salvage

Position. The patient is supine with the affected arm extended onto a radiolucent hand table, a well-padded upper-arm tourniquet exsanguinated to a bloodless field, and the whole limb prepped and free-draped so the elbow and forearm can be moved. The wrist is positioned over a bolster or rolled towels so it can be flexed β€” flexion is what delivers the proximal pole dorsally. The surgeon sits at the head of the table with the hand resting palm-down (pronated). Fluoroscopy is essential throughout, for confirming guidewire position, screw length and central screw placement. The required views are posteroanterior, lateral, semi-pronated oblique, and the scaphoid-specific ulnar-deviated view. Surface landmarks. Lister's tubercle is the dorsal prominence on the distal radius; the 3rd extensor compartment (EPL) lies immediately ulnar to it and it marks the level of the scapholunate joint. The scapholunate interval is palpable just distal to Lister's tubercle, with the scaphoid lying radial and distal to it. Further landmarks are the radial styloid (radial extent of the wrist) and the base of the third metacarpal (distal landmark, in line with the longitudinal axis of the wrist and the scaphoid). The soft-tissue landmarks are the EPL tendon (palpable as it crosses from proximal-ulnar to distal-radial around Lister's tubercle toward the thumb), the EDC tendons (just ulnar to EPL), and the anatomical snuffbox (radial to EPL distally, containing the radial artery with the scaphoid waist at its floor). Incision. A longitudinal or gently curvilinear incision approximately 4 to 6 cm long, centred over the scaphoid just distal to Lister's tubercle and in line with the long axis of the third metacarpal. Longitudinal incisions are more extensile and heal well. Stay centred over the 3rd and 4th extensor compartments to avoid the radial artery (radial) and the dorsal sensory branch of the ulnar nerve (ulnar).

The Exposure

Work down through the layers centred just distal to Lister's tubercle: protect the dorsal sensory branch of the radial nerve, open the 3rd compartment and develop the inter-compartmental interval to the capsule, make a vessel-preserving capsulotomy, then flex the wrist to deliver the proximal pole.

πŸ“·
Image Needed: Clinical PhotoHigh Priority

Intra-operative photograph of the dorsal approach to the scaphoid: a longitudinal incision just distal to Lister's tubercle, the EPL mobilised and retracted radially from the 3rd compartment, the 4th-compartment tendons swept ulnarly, and the dorsal capsule opened to expose the proximal pole and waist of the scaphoid with the wrist flexed over a bolster.

Context: A verified image is being sourced for this exposure.

Pending image generation or sourcing

Exposure sequence

Step 1Incision
  • Mark Lister's tubercle, the EPL tendon and the base of the third metacarpal.
  • Make a longitudinal (or gently curvilinear) incision approximately 4 to 6 cm long, centred over the scaphoid just distal to Lister's tubercle and in line with the long axis of the third metacarpal.
Step 2Protect the dorsal sensory branch of the radial nerve
  • Carefully incise skin and subcutaneous tissue; identify and protect the branches of the dorsal sensory branch of the radial nerve (SBRN) that cross the field.
  • Ligate or coagulate crossing veins. Do not plunge deep β€” the SBRN branches lie immediately deep to the skin.
Step 3Open the 3rd compartment and mobilise the EPL
  • Identify the EPL tendon as it crosses from ulnar-proximal to radial-distal around Lister's tubercle.
  • Incise the extensor retinaculum over the 3rd extensor compartment on the ulnar side of Lister's tubercle and mobilise the EPL tendon, sweeping it radially.
Step 4Develop the inter-compartmental interval
  • Retract the mobilised EPL radially. Gently sweep the contents of the 4th extensor compartment (EDC and EIP) ulnarly, leaving the compartment floor (the dorsal capsule) intact.
  • The interval between the 3rd and 4th compartments is now defined. There is no true internervous plane, because both tendon groups are supplied by the posterior interosseous nerve β€” this is an inter-compartmental, inter-tendinous interval, not an inter-nervous one.
Step 5Limited dorsal capsulotomy β€” preserve the dorsal ridge vessels
  • Make a limited longitudinal capsulotomy in line with the skin incision.
  • The critical step is to preserve the dorsal ridge vessels, which run transversely across the dorsum of the scaphoid waist from the dorsal carpal branch of the radial artery. Work on either side of the ridge rather than directly over it, and never strip the dorsal ridge. Stay distal and radial to the scapholunate interosseous ligament.
Step 6Deliver the proximal pole (the key manoeuvre)
  • Flex the wrist over the bolster. Wrist flexion rotates the scaphoid and delivers the proximal pole dorsally into the wound, bringing the proximal pole and waist into direct view.
  • This is the single most important exposure manoeuvre, essential for both open reduction and for the percutaneous antegrade wire entry point.
Step 7Reduction
  • For an acute fracture, reduce the proximal pole anatomically under direct vision using fine elevators, joysticks (K-wires into each fragment) and pointed reduction forceps, and confirm reduction fluoroscopically.
  • For a nonunion, freshen the fracture edges, resect fibrous tissue and prepare a dorsal trough for bone graft.
Step 8Antegrade headless compression screw
  • Place the guidewire at the proximal pole and drive it distally and volarly along the long axis of the scaphoid toward the distal pole β€” this is the antegrade direction. The ideal starting point is just radial to the central axis on the dorsum of the proximal pole.
  • Confirm central placement on posteroanterior, lateral, semi-pronated oblique and scaphoid-specific ulnar-deviated views. Measure, drill and insert a headless compression screw of appropriate length, burying it beneath the cartilage. Central screw placement maximises union.
Step 9Bone graft (when indicated)
  • For nonunion, pack cancellous autograft (or insert a corticocancellous inlay graft) into the prepared dorsal trough to restore length and vascularity before definitive screw fixation.
Step 10Closure
  • Irrigate thoroughly. Repair the dorsal capsule with absorbable sutures, taking care not to compromise the dorsal ridge vessels.
  • Repair or reconstruct the 3rd extensor compartment retinaculum over the EPL (some surgeons transpose the EPL superficially) to prevent bowstringing and adhesion. Close the subcutaneous tissue and skin and apply a well-moulded thumb-spica splint or cast.
  • Confirm screw position, length and fracture reduction on final fluoroscopy, and document neurovascular status β€” particularly SBRN sensation.
Never strip the dorsal ridge β€” it is the proximal pole's only blood supply

The dorsal carpal branch of the radial artery gives the vessels that enter along the dorsal ridge and supply 70 to 80 percent of the scaphoid, including the entire proximal pole. The proximal pole has no vascular foramina of its own and depends entirely on retrograde intraosseous flow from these vessels. A capsulotomy that strips the dorsal ridge devascularises the proximal fragment and causes avascular necrosis. Use a limited capsulotomy, work on either side of the ridge, and never strip the dorsal surface of the scaphoid.

The internervous-plane trap

If asked for the internervous plane of the dorsal approach to the scaphoid, the correct answer is that there is no true internervous plane. All the dorsal extensor tendons are supplied by the posterior interosseous nerve. The working interval is an inter-compartmental one between the 3rd compartment (EPL) and the 4th compartment (EDC and EIP). Claiming a non-existent inter-nervous plane (for example between the PIN and the superficial radial nerve) is a classic error.

Dangers & Extensions

Structures at risk, by layer

Danger structures and how to protect them
LayerStructure at riskProtection strategy
SubcutaneousDorsal sensory branch of the radial nerve (SBRN)Identify and protect branches during blunt subcutaneous dissection; avoid excessive diathermy
TendinousEPL (3rd compartment)Open the retinaculum, mobilise gently and retract radially; repair the retinaculum at closure
TendinousEDC and EIP (4th compartment)Retract ulnarly as a group; do not over-retract
CapsularDorsal ridge vessels (dorsal carpal branch of the radial artery)Make a limited capsulotomy; never strip the dorsal ridge
ArticularScapholunate interosseous ligamentStay distal and radial to the ligament during capsulotomy
VascularRadial artery in the anatomical snuffboxKeep the incision centred over the 3rd and 4th compartments; stay clear of the snuffbox
Dorsal sensory branch of the radial nerve

The most important superficial structure at risk. Branches cross the dorsum of the wrist immediately deep to the skin. Injury causes a painful numb patch on the dorsal hand and may produce a troublesome neuroma. Prevent it by identifying branches during subcutaneous dissection, protecting them with gentle retraction and avoiding excessive diathermy.

Dorsal ridge vessels

The dorsal carpal branch of the radial artery gives the vessels that enter along the dorsal ridge and supply 70 to 80 percent of the scaphoid, including the entire proximal pole. Injury devascularises the proximal fragment and causes AVN. Prevent it with a limited capsulotomy, working on either side of the ridge and never stripping the dorsal surface.

Extensor pollicis longus (EPL)

The EPL in the 3rd compartment is mobilised during the approach and is vulnerable to retraction injury and later adhesion or rupture, particularly if the screw is prominent or the retinaculum is not repaired. Prevent it with gentle mobilisation, burying the screw beneath cartilage and repairing the retinaculum.

Radial artery

Lies in the anatomical snuffbox, lateral (radial) to the approach. Not normally encountered with a centred dorsal incision, but a too-radial dissection risks laceration. Prevent it by keeping the incision centred over the 3rd and 4th compartments and staying clear of the snuffbox.

Tendon injury management. EPL irritation or rupture postoperatively is a recognised complication β€” consider retinacular reconstruction or an EIP-to-EPL transfer if rupture occurs. SBRN neurapraxia usually recovers; a symptomatic neuroma may require neuroma excision and burial. Extensile options. Extend proximally along the dorsum of the distal radius to expose the dorsal distal radius for combined distal radius and scaphoid fixation, or to harvest a pedicled dorsal vascularised bone graft such as the 1,2 intercompartmental supraretinacular artery (1,2-ICSRA) graft (continue to protect the dorsal capsular vessels and the 4th-compartment contents). Extend distally toward the base of the second and third metacarpals to expose the second and third carpometacarpal joints and dorsal metacarpals. For minimally displaced fractures, a dorsal percutaneous antegrade (Slade) technique avoids an open capsulotomy: the wrist is flexed over towels and a guidewire is introduced at the dorsal proximal pole and driven distally along the scaphoid axis under fluoroscopy. For recalcitrant nonunion with AVN, combine the dorsal approach with a vascularised bone graft (a pedicled 1,2-ICSRA graft, or a free medial femoral condyle flap for the most difficult cases); for SNAC or SLAC wrist salvage, extend into a standard dorsal wrist exposure for proximal row carpectomy or four-corner fusion. Closure principles. Repair the dorsal capsule with absorbable sutures without compressing the dorsal ridge vessels. Repair the 3rd-compartment retinaculum over the EPL (or transpose the EPL superficially) to prevent bowstringing and to glide the tendon smoothly β€” a well-repaired retinaculum reduces the risk of EPL adhesion and late rupture. Close in layers and apply a thumb-spica splint or cast. Intra-operative complications

Intra-operative complications
ComplicationPreventionManagement
SBRN injuryIdentify and protect branchesNeurapraxia observes; neuroma needs excision and burial
Dorsal ridge vessel injury and AVNLimited capsulotomy; do not strip the ridgePrevent by technique; established AVN needs a vascularised graft
MalreductionDirect visual and fluoroscopic confirmationRe-reduce before fixation
Screw prominence or intra-articular penetrationBury beneath cartilage; confirm on multiple viewsRemove or exchange the screw

Post-operative complications

Post-operative complications
ComplicationPreventionTreatment
Nonunion (higher for proximal pole and displaced fractures)Anatomic reduction, central screw, bone graft when neededRevision bone grafting; vascularised graft for AVN
Avascular necrosis of the proximal pole (highest for very proximal fractures)Preserve the dorsal ridge vesselsVascularised bone grafting
EPL irritation or ruptureBury the screw; repair the retinaculumEIP-to-EPL transfer
SBRN neurapraxia or neuromaGentle handlingObservation; neuroma surgery if persistent
InfectionAseptic technique, prophylactic antibioticsIrrigation and debridement; hardware retention if stable
Stiffness and CRPSEarly controlled mobilisation once stableHand therapy; multidisciplinary CRPS management
AVN and nonunion risk β€” the proximal-to-distal gradient

The risk of avascular necrosis and nonunion rises the more proximal the fracture, because the proximal pole is supplied only by retrograde flow from the dorsal ridge vessels. Proximal pole fractures carry the highest AVN risk; waist fractures are intermediate; distal tubercle fractures rarely develop AVN. This proximal-to-distal gradient is a favourite viva point and is the direct anatomical rationale for a careful, vessel-preserving dorsal approach.

Post-operative care. Apply a thumb-spica splint or cast, document SBRN sensation and digital perfusion, and elevate the limb. Rehabilitation: 0 to 6 weeks immobilisation in a thumb-spica cast or splint (longer for nonunion and grafting); 6 to 8 weeks radiographic union review with protected range of motion if healing; 8 to 12 weeks progressive strengthening as union confirms; and return to activity from 3 months once radiographic union is secure. Follow-up imaging is radiographs at 2, 6 and 12 weeks, with CT to confirm union when radiographs are equivocal (particularly after nonunion surgery) and MRI selectively to assess proximal pole vascularity in suspected AVN.

Procedures Through This Approach

  • Scaphoid fracture fixation β€” the principal operation done through this exposure.
  • Open reduction and antegrade headless screw fixation of displaced proximal pole fractures.
  • Percutaneous antegrade screw fixation of minimally displaced proximal pole or waist fractures.
  • Bone grafting (cancellous or corticocancellous Matti-Russe dorsal trough) for scaphoid nonunion without severe AVN.
  • Vascularised bone grafting β€” a pedicled 1,2-ICSRA graft for nonunion with proximal pole AVN, or a free vascularised medial femoral condyle flap for recalcitrant nonunion with AVN and humpback deformity.
  • Proximal pole excision or scaphoid excision for an unreconstructable fragment, or as part of a dorsal wrist salvage exposure (proximal row carpectomy, four-corner fusion).
Procedures performed through the dorsal scaphoid approach
ProcedureTypical indicationKey technical point
Open reduction and antegrade headless screw fixationDisplaced proximal pole fractureCentral screw along the scaphoid long axis
Percutaneous antegrade screw fixationMinimally displaced proximal pole or waist fractureWrist flexed; fluoroscopic central wire placement
Cancellous or corticocancellous bone grafting (Matti-Russe dorsal trough)Scaphoid nonunion without severe AVNPrepare a dorsal trough; restore length
Vascularised pedicled bone graft (1,2-ICSRA)Nonunion with proximal pole AVNPedicled on the supraretinacular artery
Free vascularised medial femoral condyle flapRecalcitrant nonunion with AVN and humpback deformityMicrovascular anastomosis; restores vascularity and length
Proximal pole excision or scaphoid excisionUnreconstructable fragment; salvage (PRC, four-corner fusion)Part of a dorsal wrist salvage exposure

Viva & Exam Focus

Mnemonic

DORSALDORSAL β€” the exposure, step by step

D
Dorsal incision
Centred just distal to Lister's tubercle, in line with the third metacarpal
O
Open the 3rd compartment
Open the 3rd extensor compartment and mobilise the EPL radially
R
Retract the tendons
EPL radial, EDC and EIP ulnar β€” the inter-compartmental interval
S
Safeguard the SBRN
Protect the dorsal sensory branch of the radial nerve, immediately deep to skin
A
Arthrotomy
Limited capsulotomy, preserving the dorsal ridge vessels
L
Lever into flexion
Flex the wrist to deliver the proximal pole dorsally into the wound

Hook:DORSAL approach β€” supine, flex the wrist, and never strip the dorsal ridge.

Mnemonic

DORSALDORSAL β€” the scaphoid blood supply

D
Dorsal carpal branch
Of the radial artery β€” the main supply to the scaphoid
O
Only 20 to 30 percent
Comes from the volar system (distal pole and tubercle)
R
Ridge vessels
Enter along the dorsal surface of the scaphoid
S
Supply 70 to 80 percent
Of the bone, including the waist and the entire proximal pole
A
AVN risk highest proximally
The proximal pole has no direct vessels β€” retrograde flow only
L
Leave the ridge intact
Do not strip it β€” preserve retrograde flow

Hook:The DORSAL vessels feed most of the scaphoid β€” protect the ridge.

Internervous plane question

There is no true internervous plane. All dorsal extensor tendons are innervated by the posterior interosseous nerve. The interval is inter-compartmental, between the 3rd compartment (EPL) and the 4th compartment (EDC and EIP). No muscle belly is divided and nothing is denervated.

Blood supply question

The dorsal carpal branch of the radial artery enters along the dorsal ridge and supplies 70 to 80 percent of the bone, including the proximal pole. A separate volar system supplies only the distal 20 to 30 percent (the distal pole and tubercle). The proximal pole has no direct vessels and depends on retrograde flow, so the dorsal ridge vessels must be preserved during capsulotomy to avoid AVN.

Screw direction question

A dorsal approach allows the screw to be placed antegrade, from the proximal pole toward the distal pole, along the long axis of the scaphoid, achieving a central position. This is the preferred direction for proximal pole fractures. The volar (RussΓ©) approach uses a retrograde (distal-to-proximal) screw for distal pole and waist fractures.

Approach selection question

Use the dorsal approach for proximal pole fractures and for nonunion grafting, where antegrade screw placement and direct proximal pole visualisation are required. Use the volar (RussΓ©) approach for distal pole and most waist fractures, where a retrograde screw avoids violating the trapezium and preserves the dorsal blood supply.

Clinical Decision Scenarios

Practise clinical reasoning and management decisions out loud

Viva scenarioStandard
Clinical prompt

β€œA 24-year-old fell on an outstretched hand and has a CT-confirmed displaced proximal pole scaphoid fracture. How would you manage this and what approach would you use?”

Practical approach
This is a displaced proximal pole scaphoid fracture, which carries a high risk of nonunion and avascular necrosis and is therefore an indication for operative fixation. The approach of choice for the proximal pole is the dorsal approach, because it gives direct visualisation of the proximal pole and allows an antegrade headless compression screw to be placed centrally along the long axis of the scaphoid. I would first confirm displacement, proximal-pole location and any sign of AVN on CT and, where relevant, MRI, and counsel the patient on the risks of nonunion, AVN, stiffness and SBRN numbness. The surgical plan is a supine position with an arm table and upper-arm tourniquet, a longitudinal dorsal incision centred just distal to Lister's tubercle, protection of the dorsal sensory branch of the radial nerve, opening of the 3rd extensor compartment with mobilisation of the EPL radially and retraction of the 4th-compartment tendons ulnarly, then a limited capsulotomy preserving the dorsal ridge vessels. I flex the wrist to deliver the proximal pole, reduce it anatomically and place an antegrade headless screw centrally, confirmed on multiple fluoroscopic views, repairing the 3rd-compartment retinaculum at closure. Post-operatively I immobilise in a thumb-spica, follow radiographs at 6 and 12 weeks with CT if union is equivocal, and counsel that proximal pole fractures carry the highest AVN risk, so vascularity must be respected throughout.
Key clinical points
Displaced proximal pole fracture is an operative indication due to high nonunion and AVN risk
Dorsal approach chosen for direct proximal pole access and antegrade screw placement
No true internervous plane β€” inter-compartmental between the 3rd (EPL) and 4th (EDC, EIP) compartments
Preserve the dorsal ridge vessels (70 to 80 percent of scaphoid blood supply) during capsulotomy
Antegrade screw placed centrally along the long axis, confirmed on multiple fluoroscopic views
Wrist flexion delivers the proximal pole into the wound
Repair the 3rd compartment retinaculum to protect the EPL
Proximal pole fractures carry the highest AVN risk
Common pitfalls
Choosing a volar retrograde screw for a proximal pole fracture, which gives poor proximal fragment purchase
Stripping the dorsal ridge and causing iatrogenic AVN
Placing the screw off-centre, reducing fixation stability and union
Failing to identify and protect the SBRN branches
Further questions
β€œHow would your management change for a minimally displaced proximal pole fracture?”
β€œWhat is the role of arthroscopic assistance in scaphoid fixation?”
β€œHow would you investigate and manage suspected postoperative AVN?”
Viva scenarioChallenging
Clinical prompt

β€œA 32-year-old manual worker has an established scaphoid waist nonunion with a sclerotic, collapsed proximal pole suggesting avascular necrosis and a humpback deformity. How do you plan surgery?”

Practical approach
This is a scaphoid nonunion complicated by proximal pole avascular necrosis and a humpback deformity (loss of scaphoid height with an extended lunate). Standard non-vascularised grafting has a poor union rate in the presence of AVN, so the principle is to restore length, alignment and vascularity. I would obtain a CT to define the nonunion, the humpback deformity (an increased intrascaphoid angle) and the lunate extension (dorsal intercalated segment instability), and an MRI to confirm proximal pole AVN, counselling the patient on the guarded prognosis and the options including salvage. Via the dorsal 3rd-to-4th-compartment interval I expose the nonunion preserving the dorsal ridge vessels where possible, open the nonunion, excise fibrous tissue and necrotic bone, and correct the humpback deformity with a corticocancellous or vascularised bone graft to restore scaphoid length and the normal intrascaphoid angle. Because of the AVN I prefer a vascularised bone graft β€” a pedicled 1,2 intercompartmental supraretinacular artery graft for most cases, or a free vascularised medial femoral condyle flap for a severe humpback deformity or a previously failed reconstruction β€” and fix it with a headless compression screw, with temporary K-wire stabilisation of the scapholunate-lunate-capitate relationship. If the proximal pole is irreconstructable or the patient is low-demand, I discuss salvage β€” proximal row carpectomy or scaphoid excision with four-corner fusion β€” particularly for established SNAC changes.
Key clinical points
Nonunion with proximal pole AVN and humpback deformity needs vascularised grafting, not simple cancellous graft
Dorsal approach provides access for graft placement and antegrade fixation
Correct the humpback deformity and restore the intrascaphoid angle
Vascularised options: pedicled 1,2-ICSRA graft, or free medial femoral condyle flap for severe or failed cases
Salvage (proximal row carpectomy, four-corner fusion) for irreconstructable or SNAC wrists
MRI confirms AVN; CT defines deformity and guides graft size
Counsel on guarded prognosis and the possibility of needing salvage
Common pitfalls
Using a non-vascularised graft in an avascular proximal pole, which has a high failure rate
Failing to correct the humpback deformity, leading to persistent carpal collapse
Not counselling the patient about the possibility of progression to salvage surgery
Damaging the dorsal ridge vessels while exposing an already devascularised proximal pole
Further questions
β€œWhat is the humpback deformity and how is it measured?”
β€œWhen would you choose a free medial femoral condyle flap over a pedicled graft?”
β€œWhat are the salvage options if vascularised grafting fails?”
Viva scenarioChallenging
Clinical prompt

β€œSix weeks after a dorsal scaphoid fixation, a patient presents with sudden loss of thumb extension and a palpable click. What is your diagnosis and management?”

Practical approach
The most likely diagnosis is rupture of the extensor pollicis longus (EPL) tendon, a recognised complication of the dorsal scaphoid approach. The EPL lies in the 3rd extensor compartment immediately adjacent to the operative field and can be injured by retraction, by a prominent screw head, by adhesion within a poorly repaired retinaculum, or by attrition over a bony ridge. I confirm the diagnosis clinically β€” loss of active thumb interphalangeal joint extension, often with a palpable or audible click, and a positive retropulsion test β€” examine for a screw prominence or hardware complication on radiographs and CT, and document neurovascular status and the state of the surgical wound. If the screw is prominent I remove or exchange it. Definitive management of an EPL rupture in this context is usually an extensor indicis proprius (EIP) to EPL transfer, which reliably restores independent thumb extension and is the standard reconstruction for EPL rupture, exploring the rupture to confirm the ends and the cause. Prevention rests on burying the screw beneath cartilage, confirming there is no dorsal prominence, gentle handling of the EPL, and repairing or reconstructing the 3rd compartment retinaculum to provide a smooth gliding surface and prevent adhesion or attrition.
Key clinical points
Diagnosis: EPL rupture, a recognised complication of the dorsal scaphoid approach
Mechanisms: retraction injury, prominent screw, adhesion, or attrition over a bony ridge
Clinical findings: loss of thumb IP extension, palpable click, positive retropulsion test
Exclude hardware prominence on imaging and remove or exchange a prominent screw
Definitive reconstruction is an EIP-to-EPL transfer
Prevention: bury the screw, repair the retinaculum, handle the EPL gently
Common pitfalls
Attributing the deficit to tendinitis or expected postoperative weakness without examining for rupture
Missing a prominent screw as the underlying cause
Not counselling the patient about the need for a tendon transfer
Failing to repair the 3rd compartment retinaculum at the index operation
Further questions
β€œWhat other extensor tendons are at risk in this approach?”
β€œHow is an EIP-to-EPL transfer performed?”
β€œHow would you prevent EPL complications in future dorsal scaphoid fixations?”
Exam day cheat sheet
DORSAL APPROACH TO THE SCAPHOID

Patient position

  • SUPINE with the arm on a hand table and an upper-arm tourniquet
  • Wrist flexed over a bolster β€” flexion delivers the proximal pole dorsally
  • Radiolucent setup with fluoroscopy for the whole case
  • Surgeon seated at the head of the hand table

Landmarks and incision

  • Lister's tubercle is the key bony landmark on the dorsal distal radius
  • EPL crosses from ulnar-proximal to radial-distal around Lister's tubercle
  • Longitudinal incision 4 to 6 cm centred just distal to Lister's tubercle
  • Stay centred over the 3rd and 4th extensor compartments; avoid the snuffbox (radial artery)

Internervous plane

  • NO true internervous plane β€” all dorsal extensor tendons are PIN-innervated
  • Inter-compartmental interval between the 3rd (EPL) and 4th (EDC, EIP) compartments
  • Open the 3rd compartment, mobilise EPL radially, sweep the 4th compartment ulnarly
  • No muscle belly is divided and nothing is denervated

Blood supply and AVN

  • Dorsal carpal branch of the radial artery supplies 70 to 80 percent via the dorsal ridge
  • Volar system supplies only the distal 20 to 30 percent (distal pole and tubercle)
  • The proximal pole has no direct vessels β€” it depends on retrograde flow
  • Preserve the dorsal ridge vessels with a limited capsulotomy; AVN risk is highest proximally

Fixation

  • Headless compression screw placed ANTEGRADE (proximal pole toward distal pole)
  • Central placement along the long axis, confirmed on multiple fluoroscopic views
  • Bone graft for nonunion; vascularised graft for proximal pole AVN
  • Volar (Russe) approach with a retrograde screw for distal pole and waist fractures

Structures at risk and closure

  • Dorsal sensory branch of the radial nerve is the key superficial structure at risk
  • Dorsal ridge vessels must be preserved to avoid AVN
  • EPL at risk of irritation or rupture β€” bury the screw and repair the retinaculum
  • Radial artery at risk only with a too-radial dissection
  • Repair capsule and 3rd-compartment retinaculum; thumb-spica splint

References

Guidelines, registries and global practice. Scaphoid fracture management is guided by international hand surgery consensus (IFSSH and FESSH), the AAOS appropriate-use criteria, and British Society for Surgery of the Hand guidance. The principles converge across examination systems (advanced orthopaedic practice or advanced orthopaedic practice, DNB and MS, MRCS, SICOT): operative fixation for displaced and proximal pole fractures, anatomic reduction with central screw placement, vessel-preserving exposure, and vascularised grafting for nonunion with AVN.

Where the guidance converges
BodyPosition on scaphoid fractures
AAOS (US)Operative fixation recommended for displaced and proximal pole fractures; percutaneous fixation reasonable for minimally displaced fractures to allow earlier return to function
BSSH and FESSH (UK and Europe)Open or percutaneous fixation for unstable and proximal pole fractures; CT or MRI to confirm occult fractures and assess vascularity; vascularised bone grafting for nonunion with AVN
AO FoundationAnatomic reduction, absolute stability with a headless compression screw placed centrally along the scaphoid axis, and bone grafting for comminution or nonunion

Population evidence. Scaphoid fractures are the most common carpal fracture, with a lifetime risk that is highest in young active men. Nonunion risk rises with displacement and with proximal fracture location; proximal pole fractures carry the highest rates of nonunion and AVN. Central screw placement and anatomic reduction are the modifiable factors most consistently associated with union. Global practice variation. In high-resource settings, percutaneous and arthroscopically assisted fixation, vascularised pedicled and free flaps, and routine advanced imaging are standard. In resource-limited settings, the same biomechanical principles are achieved with open reduction and a standard headless screw, prolonged casting for stable patterns, and cancellous autograft for nonunion, with vascularised and arthroscopic techniques used selectively. Consent (globally applicable). Discuss nonunion and AVN (highest for proximal pole fractures), stiffness, the small risk of EPL irritation or rupture, SBRN numbness or neuroma, infection, and the possible need for revision or salvage surgery.

Orthopaedic relevance

For the Operative Surgery and Hand viva, describe the dorsal approach systematically: supine positioning with wrist flexion, the inter-compartmental (not internervous) plane between the 3rd and 4th compartments, preservation of the dorsal ridge vessels supplying 70 to 80 percent of the scaphoid, antegrade central screw fixation for proximal pole fractures, and retinacular repair to protect the EPL. Know the blood supply and the proximal-to-distal gradient of AVN risk.

Evidence

The Vascularity of the Scaphoid Bone

Gelberman RH, Menon JH β€’ Journal of Hand Surgery (American Volume) (1980)
Key Findings:
  • The dorsal vascular system from the dorsal carpal branch of the radial artery enters along the dorsal ridge and supplies 70 to 80 percent of the scaphoid, including the proximal pole and waist
  • A separate volar system supplies only the distal 20 to 30 percent (the distal pole and tubercle)
  • The proximal pole has no direct vascular foramina and depends on retrograde intraosseous flow
  • Provides the anatomical rationale for the high AVN risk of proximal fractures and for vessel-preserving surgical exposure
Evidence

Management of the Fractured Scaphoid Using a New Bone Screw

Herbert TJ, Fisher WE β€’ Journal of Bone and Joint Surgery (British Volume) (1984)
Key Findings:
  • Introduced the differential-pitch headless compression screw for scaphoid fixation
  • Established the principle of rigid internal fixation that permits early mobilisation
  • Showed improved union for unstable and proximal pole fractures compared with prolonged cast treatment
  • Remains the conceptual basis for modern headless compression screw fixation of the scaphoid
Evidence

Fractures of the Scaphoid: A Rational Approach to Management

Cooney WP, Dobyns JH, Linscheid RL β€’ Clinical Orthopaedics and Related Research (1980)
Key Findings:
  • Established a rational management algorithm for scaphoid fractures based on displacement and stability
  • Reported that displaced fractures and proximal fractures have a substantially higher nonunion rate than stable waist fractures
  • Emphasised the importance of anatomic reduction and rigid internal fixation for unstable patterns
  • Foundational work underpinning modern operative decision-making in scaphoid injuries
Evidence

Percutaneous Screw Fixation or Cast Immobilization for Nondisplaced Scaphoid Fractures

Bond CD, Shin AY, McBride MT, Dao KD β€’ Journal of Bone and Joint Surgery (American Volume) (2001)
Key Findings:
  • Randomised trial comparing percutaneous screw fixation with cast immobilisation for nondisplaced scaphoid fractures
  • Percutaneous fixation allowed a significantly faster return to work and sport than casting
  • Union rates were comparable between the two groups
  • Supported the trend toward percutaneous fixation in active patients with nondisplaced fractures
Evidence

Treatment of Scaphoid Nonunions: Quantitative Meta-analysis of the Literature

Merrell GA, Wolfe SW, Slade JF III β€’ Journal of Hand Surgery (American Volume) (2002)
Key Findings:
  • Quantitative meta-analysis of scaphoid nonunion treatment across the published literature
  • For nonunion without AVN, screw fixation with cancellous bone grafting achieved high union rates
  • For nonunion with avascular necrosis, vascularised bone grafting achieved substantially higher union rates than conventional non-vascularised grafting
  • Informs the choice of vascularised over non-vascularised grafting when the proximal pole is avascular
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